Temperature sensing with chipless RFID-based sensors has been an area of intense research (Amin & Karmakar, 2011; Mahmood, Sigmarsson, Joshi, Chappell, & Peroulis, 2007; Mandel et al., 2011; Preradovic, Kamakar, & Amin, 2011; Preradovic & Karmakar, 2010; Thai et al., 2010, 2012; Traille et al., 2011; incorporated by reference in their entireties). The proposed sensors can be separated into two different groups: a first group where the tag's resonators are connected to a resistive or capacitive sensor, changing the resonator's quality factor (and therefore the RCS level) or the resonant frequency respectively. The sensors in the second group rely on materials which dielectric permittivity changes with temperature. For example, stanyl polyamide is used as a superstrate of a spiral resonator (Amin, Saha, & Karmakar, 2014; incorporated by reference in its entirety). The dielectric permittivity of this material is very sensitive to changes in temperature, therefore when temperature changes the effective dielectric permittivity seen by the resonator changes, producing a frequency shift in its resonant frequency that can be detected and used to estimate the temperature. In a different approach, but relying in the same principle, a double split ring resonator is loaded with a MEMS based capacitor (Thai et al., 2012; incorporated by reference in its entirety). The capacitor is formed with a micro-cantilever that is built using two different materials with different thermal expansion coefficients. Due to this difference in thermal expansion coefficients, temperature changes produce a bent in the cantilever, changing its series capacitance resulting in a frequency shift in the resonator that is used to estimate the temperature. Although important, there are many applications for which the absolute temperature is not as important as detecting when a certain temperature threshold is crossed. The food (especially produce) supply chain, biological storage and chemical storage are some applications where it is important to ensure that a given threshold temperature is not crossed. In these cases, a sensor that detects this violation of the threshold temperature and stores this information is desired. Although most applications in the cold supply chain are concerned with temperatures remaining below a given threshold (e.g. ice cream, which should not soften or melt in the supply chain), the invention disclosed herein is also applicable to cases in which the temperature should not be too cold; it is the change in dielectric properties of the temperature-sensitive material that gives rise to a corresponding change in radio frequency signature of the tags.